Star diblock copolymers

D. Y. Zhao, Q. S. Huo, J. L. Feng, B. F. Chmelka, and G. D. Smcky, Nonionic triblock and star diblock copolymer and oligomeric surfactant syntheses of highly ordered, hydrothermally stable, mesoporous silica structures, J. Am. Chem. Soc. 120(24), 6024-6036 (1998). 

Fig. 19 Schematic representation of block-arm star copolymer of type (PS- -P2VP) (PS) and (PS) (P2VP) heteroarm star diblock copolymer complexed with DBSA. In the drawing n = 4, Reprinted with permission from [135,136]. 2005 and 2006 American Chemical Society...

Figure 4.27 Traiumission electron micrographs of a mixture of a star diblock copolymer (polybutadiene-polystyrene) with a homopolymer (polystyrene). The upper EM images show mesh layers viewed end-on. The lower image shows the mesh sheets viewed from above, revealing the dense network of pores in the layers, so that the sheets are in fact a filigree of interconnected tunnels. The large-scale dark (one marked A) and bright (B) fringes are due to variations in the thickness of the specimen only. Pictures reproduced witti permission from [48].

In 1986, Thomas et al. were the first to discover the double-gyroid IMDS in multiarm star diblock copolymers of poly(isoprene) and poly(styrene), but incorrectly identified the new morphology, lying between the lamellar and cylindrical phase, as the... 

QuagUa, F., Ostacolo, L., De Rosa, G., La Rotonda, M.I., Ammendola, M., Nese, G., et al. Nanoscopic core-shell drug carriers made of amphiphilic triblock and star-diblock copolymers. Int. J. Pharm. 324(1), 56-66 (2006)... 

Arm star diblock copolymer Figure 2 Star-block copolymers. 

Discuss feasible routes for the synthesis of narrow-disperse (a) four-armed star polymer, core-(PCLso)4 (where CL = caprolactone) and (b) four-armed star diblock copolymer, core-(PCLso-fc-PStso)4 (where PSt = polystyrene). Calculate the theoretical molecular weights of the star (co)polymers. [Ans. (a) 22,936 (b) 44,332.]... 

De la Cruz and Sanchez [3] have calculated, using a mean-field theory, the phase stability criteria and static structure factors for n-arm star diblock copolymers [(AB) star]. According to their calculations, as n becomes large, the (AB) star begins to develop a core-and-shell structure. The core is rich in A monomer and the shell is rich in B monomer even in the disordered state. 

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